Signedon top of slider: MADE IN U.S.A. / CENTRAL SCIENTIFIC Co. / AMP. 19.4 8.6 5.8 OHM / CENCO RHEOSTAT / BOSTON CHICAGO TORONTO / NEW YORK LOS ANGELES
FunctionA rheostat functions as a variable resistance or as a voltage divider. If one end of the metal cylinder and the electrical contact that slides above are connected to a circuit, the rheostat works as a variable resistance. It can be altered by moving the point of contact on the cylinder's metal strip. If one connects the other end of the cylinder, the movable contact becomes a voltage divider: one can get from the movable contact any voltage between those at the two ends of the cylinder.